import math

x1, y1, x2, y2 = [float(s) for s in input().split()]
print(math.sqrt((math.fabs(x1 - x2) ** 2) + (math.fabs(y1 - y2) ** 2))) import math math float(s) for s in input().split() for s in input().split() s input().split() ().split () input split for s in input().split() float(s) float s x1, y1, x2, y2 = [float(s) for s in input().split()] x1 [float(s) for s in input().split()] y1 x2 y2 print(math.sqrt((math.fabs(x1 - x2) ** 2) + (math.fabs(y1 - y2) ** 2))) print math.sqrt((math.fabs(x1 - x2) ** 2) + (math.fabs(y1 - y2) ** 2)) math.sqrt math sqrt (math.fabs(x1 - x2) ** 2) + (math.fabs(y1 - y2) ** 2) math.fabs(x1 - x2) ** 2 math.fabs(x1 - x2) math.fabs math fabs x1 - x2 x1 x2 2 math.fabs(y1 - y2) ** 2 math.fabs(y1 - y2) math.fabs math fabs y1 - y2 y1 y2 2 y1, x2, y2 = [float(s) for s in input().split()] [float(s) for s in input().split()] y1 x2, y2 = [float(s) for s in input().split()] [float(s) for s in input().split()] x2 y2 = [float(s) for s in input().split()] [float(s) for s in input().split()] y2 x1, y1, x2, y2 = [float(s) for s in input().split()] [float(s) for s in input().split()] x1
import math

x1, y1, x2, y2 = [float(s) for s in input().split()]
print(math.sqrt((math.fabs(x1 - x2) ** 2) + (math.fabs(y1 - y2) ** 2)))